Measured-service automatic telephone system



Aug. 10,1926. 1,595,126 P. C. SMITH MEASURED SERVICE AUTOMATIC TELEPHONE SYSTETI Original Filed June 20. 1922 Patented Aug. 10, 1926.

UNITED STATES- PATENT OFFICE.

PERCY C. SMITH, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

MEASURED-SERVICE AUTOMATIC TELEPHONE SYSTEM.

Original application filed June 20, 1922, Serial No. 569,700. Divided and this a'pplication filed November 24, 1924. Serial No. 751,754.

This invention relates to automatic telephone systems and more particularly to a metering circuit arrangement for systems of this character.

It is a division of the application, Serial No. 569,700, filed June 20, 1922, Patent 1,542,105, June 16, 1925. v

The object of the invention is to provide an improved circuit arrangement for automatically operating the calling line meter on ordinary calls when the called station answers and for preventing the operation of the calling line meter on so-called free calls; that is, on calls to oflicials of the telephone company or the police or fire departments.

In accordance with this invention, these free lines are placed in a certain level or levels of the connector'which is provided with means actuated only when the connector is set on one of said levels to supply current to the calling line without effecting a circuit change in the calling line to cause the meter to record the call. But if the connector is set on any other level in connecting with the called line, this means is rendered inoperative and the direction of the flow of current supplied to the calling line is reversed causing the meter to record the call.

Referring to the drawing which comprises but a single sheet, a calling station 1 is shown at the left and a called station 2 vat the right. These stations are interconnected by means of one or more selector switches such as the one represented by the brushes 13, 14: and and a" connector switch such as the one shown in detail in the drawing.

Only so much of the circuits are shown as is necessary tocomprehend the invention. This invention may be incorporated in a system such as the one shown in the patent to Wicks No. 1,379,068, issued May 24, 1921, and Reissue No. 15,762 of February 12,1924.

It is thought that the invention will be more clearly understood from the detailed description of the operation of the system.

When the receiver is removed at the calling station 1, circuits are closed to extend the connection by way of the brushes 4:, 5, 6, and 7 to the terminals 8, 9, 10 and 11 at the selector switch. The dial 3 at the calling station is now operated and the selector switch is operated, the brushes 13, 14: and 15 of which are set upon the terminals 58, 59 and 16 respectively, of the connector switch.

It should be understood that one or more other selector switches may, if desired, be used in conjunction with the selector switch shown to extend the connection to the terminals 58, 59 and 16 of the connector switch. In any event, the calling station 1 is extended to the connector switch and a circuit is closed including the windings of the impulse relay 27 and the calling station loop operating the impulse relay 27. The operation of relay 27 closes'an obvious circuit to operate the slow to release relay 28 which connects ground through its right hand inner armature and front contact to the test terminal 16, thence via 15, 10 and 6 to the winding of relay 30 which remains operated under control of relay 28. Relay 39 which is connected in series with the im pulse relay 27 in the calling station loop is polarized and does not operate at this time. i

hen the dial 3 is operated in accordance with the hundreds digit of the called line number which we will assume to be the called station 2, the impulse relay 27 releases closing a circuit to operate the primary magnet PM and relay 29 in series. The primary magnet operates and releases in accordance with the number of impulses produced by the impulse relay 27 but relays 29 and 28 which are slow to release remain operated throughout the impulse period. The primary magnet PM inv operating raises the brush shaft carrying the brushes 20, 21, 22 and d2 a number of steps dependent upon the number of impulses transmitted by the dial 3.

When the brush shaft is raised one step, the off normal contact springs ON are operated, opening contact and closing contact 61. The brush 4:2 is secured to the brush shaft and moves in unison therewith thus passing over the contacts such as 43 of the commutator with which it is associated. the end of the impulse period, relay 27 remains operated and relay 29 releases. The brushes 20, 21 and 22 are now resting opposite the terminals of the first line in the level selected, in which level we will assume the terminals 23, at and 25 associated with the called station 2 shown inthe drawing to be located.

The dial 3 is now operated and released in accordance with "the units digit of the called line, in this c'asethe digit-1, and the impulse relay 2? is again released and reoperated in accordance with the'impulses'produced by the dial 3. When the impulse relay 2'? releases, a circuit is closed to operate the secondary magnet SM andthe slow to releas relay 31 in parallel. The operation of the secondary magnet SM rotates the brushes 20, 21 and 22 one step to the terminals 23, 24 and 25 associated with the 2 Relay 31 is designed tobe slow to release so that it will remain op,

called station 2.

test

I and front contact of relay 31, crush 22 and terminal 25 to ground. ll hen relay releases,*'relay 32 will lock by way of its inner "right hand armature and front contact to ground under control of relay Belay 32 operated connects the winding of the transformer B'lto the conductor 45 of the connector circuit whereby high frequency current. is transmitted to the calling station 1 'to lndicate that the called hue is husv.

Assuming, however, that the called station 2 is idle at the time the brushes 20, 21. and 22 come to rest upon the terminals 23, 24 and'25,-the relay 32 will not operate and when relay 31 releases a circuit will be closed to operate relay 19 as follows: battery, winding of relay 41, 25, 22, left hand armature and normal contact of relay 31, upper winding of relay 19, right hand inner armature and normal Contact of relay 32, right relay 28 to ground. Relay 19 operated locks through its lower winding under control of armature 57 of relay 28.

"iignaling current is now connected 'to th called station 2 as follows: grounded alternator 33, drums 34 and 35, 46, 47, 21, 24, called station 2, 23, 20, 48, 49, upper winding of relay 26 to ground. The called station is thereat, relay 26 is operated through its upper winding either in series with the alternator 33 or the source of battery supply con nected to the drum 36. Relay 26 operated looks through its lower winding under control of armature 57 of relay 28. The called. station is now connected to the windings of relay 38 battery, upon winding of relay 38, 45, 46, 4?, 21, 24, called station 2,23, 20,48, 49, 5o, 51 lower winding of relay 38, 52, 53, 54, 55, 56, 57-to ground. Relay 38 operated, reverses the direction of thefiow of'c'urrent iZed relay 39 whicli operates closingat armature 12 a circuit including thewinding supplied through the-impulse relay 2? to the calling station 1. This reversal reverses in flow of current in the winding of the of the message register 40 thus charging the "call.

movement of the switch the hrush 42 will be resting upon one of the terminals such as the-terminal 43 which is connected to the winding of relay 37. It should understood that the brush 42 makes contact with the teri'ninals of the associated commutator during the primary movement of the switch hut remains in contact with a particular ter min al during the secondary movement of the switch and throughout the conversation,

'only'being separated, therefronrwhen the switch is restored to its normal position.

Assuming then that the brush 42 isres'ting uponthe terminal 43 or some other terminal connected to the winding of relay 3?, the latter relay will be connected in parallel with the upper winding of relay 38.; When the receiver is removed at the fc alled station 2, relays 37 and 38 will operate in parallel, the latter reversing the direction of the flow of current.suppliedto the calling station 1 throughthe windingsof the impulse relay 27 in the manner previously described. The operation of relay 37,l1owever, causes the direction of theflow of current supplied through the impulse relay 27 to the calling station 1 to he again reversed thus immediately changing the direction of the current flowing through the winding of the polarized relay 39 and the calling station 1 'to the original condition. Under-these circumstances, the polarized relay 39'will not operate'and the calling stahand inner armature and front contact of .slow to release r'elay28 whichalso releases.

When the receiver a is replaced upon the switchlioolcat the called station 2, relay 38 releases closing a circuit to operate the release magnetREL which restores 'the consignaled and when the receiver is removed nector swear to normal.

VVhat is 'claimecl is: 1-.fIn" a telephone system, callingfand called telephone lines, 'an" autoiiiatic switch for" interconnecting the same wl' er'ein said called lines terminate n. groups, meters for said calling lines, means 'in' said switch responsive to the reino'valof the "receiver of which operates over the following'circuitr the called line for operating the calling line meter, and means 'infsa-id switch responsiyeto' the removal of the receiver o the called line actuated"only when said auton'i'atic switch selects 21' called line in a ce'rtaingroup for renderingsaid meter opcrating means inefiective to operate said meters.

2.111 a telephone system, calling and called telephone lines, automatic switches for interconnecting the same including a connector wherein said called lines terminate in levels, meters for said calling lines, means in said connector responsive to the removal of the'receiver of the called line for causing the operation of the calling line meter, and means in said connector responsive to the removal of the receiver of the called line but actuated only when the connector is set on certain levels for rendering said meter operating means ineffective to operate said meters.

3. In a telephone system, calling and called telephone lines, an automatic switch for interconnecting the same wherein the called lines terminate in groups, meters for said calling lines, means in said switch re sponsive to the removal 01" the receiver of the called line for controlling the operation of the calling line meter, and means in said switch responsive to the removal of the receiver of the called line actuated only when said automatic switch selects a called line in certain groups for rendering said first mentioned means ineflective to operate said meters.

l. In a telephone system, a calling line, a call charging register for said line, an automatic switch, other telephone lines including free lines accessible to the calling line via said switch, a polarized relay for controlling the register, a circuit including the polarized relay and a calling line, means included in the switch responsive to the removal of the receiver of a called line for operating the polarized relay to charge a call, and means included in the switch responsive only to the removal of the receiver of a tree line for rendering said first mentioned means ineiiective to operate said relay.

5. In a telephone system, calling and called telephone lines, an automatic switch for interconnecting the same, wherein the called lines terminate in groups, meters for said calling lines, a relay in said switch responsive to the removal of the receiver of the called line for controlling the operation of the calling line meter, and a second relay in said switch responsive to the removal of the receiver or the called line and actuated only when said automatic switch selects a called line in certain groups for rendering said first mentioned relay ineffective to operate said meters.

6. In a telephone system, a calling line, a call charging register for said line, an automatic switch, other telephone lines including free lines accessible to the calling line via said switch, a polarized relay for controlling the register, a circuit including the polarized relay and the calling line, a second relay included in the switch responsive to the removal of the receiver of the called line for operating the polarized relay to charge a call, and a third relay inemded in the switch responsive only to the removal 01"? the receiver of a tree line for rendering said polarized relay ineffective to operate said second relay,

In witness whereof, I hereunto subscribe my name this 21st day of November A. D.,

PERCY 0. SMITH. 

